OS/2 stands for operating system/2, an operating system that was developed by Microsoft C01poration and IBM, and now being improved and marketed exclusively by IBM. OS/2 runs on 286-, 386-, and 486-based IBM PCs and compatibles. OS/2 has many of the same commands as DOS, can read DOS disks, but it is more sophisticated than DOS. In particular, OS/2 is a multi-tasking, multi-threaded operating system. Multi-tasking means it can run more than one application at a time; multi-threaded means that a single program can perform multiple separate tasks at the same time.
OS/2 also includes a graphical user interface, or GUI, called Presentation Manager, and which makes OS/2 look and work something like the Macintosh or Windows. Using Presentation Manager is optional, depending on the software you run; if you’d rather, you can type commands on a command line in character mode, just as in DOS. OS/2 also comes with LAN Manager software for networking (connecting several computers together so they can share information).
If you read PC-oriented magazines, you’ll see lots of arguments about which is better, OS/2 or Windows. From a strictly technical standpoint, OS/2 is superior: it’s theoretically less prone to crashing; it uses a better type of multi-tasking (called per-emptive multi-tasking) that gives you more control over which application gets priority; and permits multi-threaded applications, which Windows doesn’t. OS/2 runs most DOS and Windows programs, though Windows programs run more slowly than they do under Windows 3.1. Although OS/2 is really popular in corporate MIS circles because of its excellent mainframe connectivity and application development tools, Windows is more popular by far, and for that reason far more applications and utilities designed for Windows are available than for OS/2, and more kinds of hardware devices work with Windows.